This page describes a tester device, which is capable of programming a BIOS ROM chip while it is connected to a live mainboard. The tester is controlled by a host PC via USB. The purpose of this tester device is to provide a do-it-yourself hardware for testing Coreboot builds. The goal is to support automated builds and tests from version control repository.

This page describes a tester device, which is capable of programming a BIOS ROM chip while it is connected to a live mainboard. The tester is controlled by a host PC via USB. The purpose of this tester device is to provide a do-it-yourself hardware for testing Coreboot builds. The goal is to support automated builds and tests from version control repository.

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The tester is built around the Atmel AT90USB162 microcontroller, which is programmed using avr-gcc and the LUFA library. The host-side software is currently [[Flashrom]].

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The tester can program the ROM chip regardless of the state of the mainboard. Therefore it is suitable for testing experimental Coreboot builds, which may or may not be able to boot properly.

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The tester is built around the Atmel AT90USB162 microcontroller, which is programmed using avr-gcc and the LUFA library. The host-side software is currently [http://flashrom.org flashrom].

=Features=

=Features=

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* Tester consists of two circuit boards: main and auxiliary board. Main tester board connects to host via USB, and to aux board via ribbon cable.

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* Tester consists of two circuit boards: main and auxiliary board. Main tester board connects to host via USB, and to aux board via ribbon cable.

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** Smaller boards are easier to build

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** Minimize the size of tester to be plugged into mainboard, in case there are obstructions.

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** Modular hardware to later accommodate other ROM types besides SPI.

* Optionally, the main tester board can be connected to the reset and ATX power pins of the target mainboard. All common sense voltages (1..5V) are supported.

* Optionally, the main tester board can be connected to the reset and ATX power pins of the target mainboard. All common sense voltages (1..5V) are supported.

* The main tester board has a standard serial port for reading debug output from the target mainbaord.

* The main tester board has a standard serial port for reading debug output from the target mainbaord.

* PCB layout is kept simple, so that it can be built using hobbyist methods, e.g. toner transfer PCB etching. The parts have been chosen so that they should be quite well available and inexpensive.

* PCB layout is kept simple, so that it can be built using hobbyist methods, e.g. toner transfer PCB etching. The parts have been chosen so that they should be quite well available and inexpensive.

* Designed using open source tools.

* Designed using open source tools.

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* The auxiliary board can be powered from either the tester or the mainboard.

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** Tester can operate and reprogram ROM even while target mainboard has no power.

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** Target mainboard can operate normally while tester has no power.

=Status=

=Status=

Line 19:

Line 27:

* Current firmware and flashrom extension do not support serial port or reset/power switch operation.

* Current firmware and flashrom extension do not support serial port or reset/power switch operation.

The AVR firmware is based on the [http://www.fourwalledcubicle.com/LUFA.php LUFA] library. Version 101122 was used in development.

=Host-side software=

=Host-side software=

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The current host-side software is [http://flashrom.org flashrom] and its [http://flashrom.org/Serprog serprog module]. It basically tunnels the SPI traffic over a serial port over USB. (This is a bit silly design, and should be replaced. It was used to enable quick testing with standard Linux kernel USB CDC driver on the host side and easy flashrom modification, but now works even on Windows and is used by a number of other programmers due to its simplicity...)

=Downloads=

=Downloads=

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Download sources from Git repository.

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Download hardware, firmware, and sources from Git repository:

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TODO: Add URL here.

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$ git clone http://alpskari.asiantuntijat.org/~juhe/isf.git

Latest revision as of 14:22, 2 April 2013

Contents

Introduction

Tester device prototype 1 connected to mainboard

This page describes a tester device, which is capable of programming a BIOS ROM chip while it is connected to a live mainboard. The tester is controlled by a host PC via USB. The purpose of this tester device is to provide a do-it-yourself hardware for testing Coreboot builds. The goal is to support automated builds and tests from version control repository.

The tester can program the ROM chip regardless of the state of the mainboard. Therefore it is suitable for testing experimental Coreboot builds, which may or may not be able to boot properly.

The tester is built around the Atmel AT90USB162 microcontroller, which is programmed using avr-gcc and the LUFA library. The host-side software is currently flashrom.

Features

Tester consists of two circuit boards: main and auxiliary board. Main tester board connects to host via USB, and to aux board via ribbon cable.

Smaller boards are easier to build

Minimize the size of tester to be plugged into mainboard, in case there are obstructions.

Modular hardware to later accommodate other ROM types besides SPI.

Optionally, the main tester board can be connected to the reset and ATX power pins of the target mainboard. All common sense voltages (1..5V) are supported.

The main tester board has a standard serial port for reading debug output from the target mainbaord.

PCB layout is kept simple, so that it can be built using hobbyist methods, e.g. toner transfer PCB etching. The parts have been chosen so that they should be quite well available and inexpensive.

Designed using open source tools.

The auxiliary board can be powered from either the tester or the mainboard.

Tester can operate and reprogram ROM even while target mainboard has no power.

Target mainboard can operate normally while tester has no power.

Status

Currently supports SPI ROMs only.

Current firmware and flashrom extension do not support serial port or reset/power switch operation.

Auxiliary PCB

U3: DIP-8 pin header on the solder-side of the board (plugs to mainboard ROM socket)

C1,C2: Power bypass capacitors. 100nF worked fine.

D1,D2: Schottky diodes with low forward voltage drop. Here SD103A-T/R

R1: Pull-up resistor. 120 kohm was used.

J1: 2x5 pin header for connecting to tester main PCB. Pins 7 and 8 are not used.

Firmware

The AVR firmware is based on the LUFA library. Version 101122 was used in development.

Host-side software

The current host-side software is flashrom and its serprog module. It basically tunnels the SPI traffic over a serial port over USB. (This is a bit silly design, and should be replaced. It was used to enable quick testing with standard Linux kernel USB CDC driver on the host side and easy flashrom modification, but now works even on Windows and is used by a number of other programmers due to its simplicity...)